Typically in low lying buildings such as in schools, a crawl space is located beneath the first floor which includes classrooms and offices. Oftentimes, the height of the crawl space is less than would be required for a person to walk erect and therefore, the use of the crawl space is limited. Typically, lengths of utility lines such as pipes and wiring extend through the crawl space to communicate between different areas of the overhead building.
The ceiling of the crawl space forms the floor for the first floor of the building and the floor of the crawl space is formed by unexcavated earth into which concrete supports, walls or foundation walls formed of masonry blocks, have been erected to define the side walls of the crawl space. The concrete supports, walls or foundation walls formed of masonry blocks, support the building overhead, typically of one to three floors in height. Additional support may be provided by columns of concrete, masonry block or steel placed throughout the crawl space or at the perimeter support walls.
As has recently been publicized, many public facilities, such as schools, have been found to include asbestos containing materials such as insulation surrounding pipes, duct work and conduits and insulation or fireproofing for the building. It is essential that the asbestos contamination be removed from these facilities with minimum exposure to airborne asbestos particles so as to minimize the health hazard to the asbestos removal workers as well as those who will be using the building after the asbestos has been removed.
A problem encountered in the crawl space of low lying buildings which include different forms of asbestos insulation or fireproofing is that over time, the asbestos insulation or fireproofing, such as for example pipe lagging which includes asbestos particles, deteriorates and falls by gravity to the exposed earth below. Anyone attempting to make repairs to any of the utilities located in the crawl space are not only exposed to the asbestos contamination from the deteriorating insulation or fireproofing but by treading on the earthen floor, the asbestos contamination which has already fallen to the ground is disturbed and becomes airborne, which is its most dangerous condition.
A proposed solution to this problem has been to excavate a substantial amount of earth from the crawl space to a predetermined depth to ensure removal of the asbestos particles which have fallen to and mixed with the earthen floor. Due to the limited area of movement in a crawl space and the amount of earth which would be required to be removed, this solution would prove quite costly and time consuming. An alternate solution has been to pour a thin layer of concrete over the earthen floor. Due to the limited area of movement in a crawl space this solution also has proven to be time consuming and costly.